Tweet-a-Watt kits now available…


Tweet-a-Watt kits are now available! A few months ago, using “off-the-shelf hardware”, we modified a Kill-a-Watt(TM) power meter to “tweet” (publish wirelessly) the daily KWH consumed to the user’s Twitter account (Cumulative Killowatt-hours). We released this project as an “Open source hardware” project – in other words, anyone can make these, modify them and make a commercial product from the ideas and methods.

After we released this project we entered it in the Greener Gadgets design contest and won first place, we donate the winnings to “Engineers without borders“.

You can see the “Tweetawatt” account on twitter here!

3208929592 8D6F1805D0 O

Here’s how it works, the modified Kill-a-Watt uses a “super-cap” to slowly recharge itself, once there is enough power it turns on the Xbee wireless module which transmits the data to a nearby computer (or internet connected microcontroller, like an Arduino) once the power usage for the day is recorded it uses a predefined Twitter account (it can be your own) to publish your daily KWH consumption for the day, multiple units can be used for an entire household.

3208084037 3Eeeb8Fcd3 O

Energy change and consumption can happen many ways, we feel there is a social imperative and joy in publishing one’s own daily KWH – by sharing these numbers on a service like Twitter users can compete for the lowest numbers and also see how they’re doing compared to their friends and followers. Our system can work with twitter, google app engine or really… anything that can display data.

We also wanted to make it easy for anyone to build these so we have released a kit based on the inquires and demand – you don’t need to be a venture backed company or a giant company with millions of dollars to make your own low cost home power monitoring system.

Please note Kill-a-Watt(TM) power meters are not included, you can get these just about anywhere for less than $20.

We have two versions of the kits…

Tweetstart Lrg

Tweet-a-Watt starter pack

Tweet-a-Watt is a DIY wireless power monitoring system. The project uses an ‘off the shelf’ power monitor called the Kill-a-Watt and adds wireless reporting. Each  plug transmits the power usage at that outlet to a central computer receiver. The receiver can then log, graph and report the data. This pack contains nearly everything* necessary to build a single outlet monitor and receiver. To monitor additional outlets, you will need an add-on transmitter pack. One outlet can monitor up to 1500 Watts.

The starter pack contains:

  • 2  XBee modules (one for receiver, one for transmitter)
  • 2  XBee adapter kits (ditto)
  • 1  USB FTDI cable (for updating, configuring and receiving data from XBee)
  • 1  bag of parts including 10,000uF capacitor, 220uF capacitor, 2 1% 10K resistors, 2 1% 4.7K resistors, 5mm green LED, 6″ rainbow ribbon cable, and 2 pieces of 1/8″ and 1/16″ heatshrink

In stock now at the Adafruit store

Tawaddon Lrg

Tweet-a-Watt add-on outlet kit

This pack contains parts to make an additional outlet for your Tweet-a-Watt setup.

Included is:

  • XBee module
  • XBee adapter kit
  • Bag of parts including 10,000uF capacitor, 220uF capacitor, 2 1% 10K resistors, 2 1% 4.7K resistors, 5mm green LED, 6″ rainbow ribbon cable, and 2 pieces of 1/8″ and 1/16″ heatshrink

Tweet-a-Watt kits are now available in the Adafruit store.

Adafruit publishes a wide range of writing and video content, including interviews and reporting on the maker market and the wider technology world. Our standards page is intended as a guide to best practices that Adafruit uses, as well as an outline of the ethical standards Adafruit aspires to. While Adafruit is not an independent journalistic institution, Adafruit strives to be a fair, informative, and positive voice within the community – check it out here:

Join Adafruit on Mastodon

Adafruit is on Mastodon, join in!

Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.

Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7pm ET! To join, head over to YouTube and check out the show’s live chat – we’ll post the link there.

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Join over 36,000+ makers on Adafruit’s Discord channels and be part of the community!

CircuitPython – The easiest way to program microcontrollers –

Maker Business — “Packaging” chips in the US

Wearables — Enclosures help fight body humidity in costumes

Electronics — Transformers: More than meets the eye!

Python for Microcontrollers — Python on Microcontrollers Newsletter: Silicon Labs introduces CircuitPython support, and more! #CircuitPython #Python #micropython @ThePSF @Raspberry_Pi

Adafruit IoT Monthly — Guardian Robot, Weather-wise Umbrella Stand, and more!

Microsoft MakeCode — MakeCode Thank You!

EYE on NPI — Maxim’s Himalaya uSLIC Step-Down Power Module #EyeOnNPI @maximintegrated @digikey

New Products – Adafruit Industries – Makers, hackers, artists, designers and engineers! — #NewProds 7/19/23 Feat. Adafruit Matrix Portal S3 CircuitPython Powered Internet Display!

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at !


  1. we should give john park a metal for calling this on AOTS a few weeks ago.

    glad to see another great kit!

  2. “You kid’s get off my lawn! and you owe me $0.31”

    Now my motion activated security light will inform a twitter account how much those kids owe me in electricity for turning on the lights.
    Or perhaps charging a prowler for economic damages?

  3. What I think would be absolutely awesome would be to remotely control the power of this, as well. For instance, have some sort of server that store parameters. Then, the tweet-a-watt (or other hacked kill-a-watt) notifies the system that currents watts have hit X level.

    I think it would be great to set a schedule for my television and DVD player. Combined, they drawn 18 watts of power when they are turned off. 70 watts if they are on. So, if the watts drop below 30 between the hours of 12P-6P (when no one is home), and 9P-6A (when we are likely to be asleep), then turn off the power to the connected device(s), making the power available again after that time is expired.

  4. This kit is just awesome!

  5. Interesting idea Dus10. You can in fact get “standby power” devices which will monitor the power usage of a device (eg TV) and when it detects the standby mode (ie. Power draw has dropped to a set level) it will open a switch automatically. You can then turn the device back on, some have IR remote control. Great for reducing standby power usage, which can get quite large.

    I would suggest taking your idea one step further. When your total power usage hits X kWh, start turning off “unnecessary” devices (fans, radios, lights, etc) according to what you deem is required. This way you could force your energy usage down!

  6. Since this requires an always-on Internet connected device, how much electricity is used sending worthless tweets all days?

  7. @aep528 – please read the site, you do not need to use an “always-on Internet connected device” – and as far as how “useful” any tweet is… please give an example of a useful one.

  8. Can this XBee adapter be used with XBeePRO for transmission upto 1 mile ???

  9. Hey aep528 keep looking really hard to the horizon and if conditions are perfect eventually you will see all the way to the end of your nose.

  10. Arthur Grumbine

    @iaindb & Dus10

    You guys (along with the apparent ease of this kit) have totally inspired me to begin again my plan for a DIY Total Home/Small-Office Power Monitoring AND Management System. How awesome will it be to never have to be concerned about whether you left X, Y or Z devices on when you’re away from the home/office. To be able to rest comfortably in the knowledge that you are as power-efficient as you want to be, AND to be able to test the effects/power-consumption of new/replacement devices…again, awesome!

  11. thanks arthur – our goal was to inspire others! please let us know how your project works out and post some photos, etc!

  12. I just encountered mention of the Tweet-a-Watt somewhere I didn’t expect it: The American Society of Mechanical Engineers’ Magazine, Mechanical Engineering. (p. 9, April 2009) This is an exciting idea that is certainly in keeping with the rest of the cool stuff Adafruit has produced and deserving of the first place award.

    Keep up the good work!

  13. Travis, do you think you could snap a photo or scan? I wonder what it says!

  14. Can do. I’ll post it in the general forum under the Tweet-a-Watt category.

  15. Scaling this to every house, one should get the power switches in the distribution box of every house, to include the following.

    1. Measure watts of power flowing.
    2. Allow for low power wireless interrogation.
    3. Future, maybe logging every 10min. (Need 200 to cover 24h)

    Would be great if you could just swap-out a relay and suddenly have visibility on that circuit, be it the geyser, lights or some plugs in the house.

Sorry, the comment form is closed at this time.